Compound 3-Cyano-4,6-dimethyl-5-(4′-nitrophenylazo)-pyridine-2(1H)-one was synthesised previously as per the following literature reference:
Dusan Mijin, Gordana Uscumlic, Nada Perisic-Janjic, Ivan Trkulja, Maja Radetic and Petar Jovancic, “Synthesis, properties and color assessment of some new 5-(3- and 4-substituted phenylazo)-,6-dimethyl-3-cyano-2-pyridones” J. Serb. Chem. Soc. 71 (5) 435-444 (2006)